Registry / devops / async-local-storage

async-local-storage

library2.3.1jsnpmunverified

An async hooks-based thread-local-like storage for Node.js, providing per-call-chain context propagation. Version 2.3.1 supports Node >=8.0.0 using async_hooks. It offers scopable storage, linked top behavior, and create time tracking. Compared to alternatives like cls-hooked or async_hooks directly, it provides a simpler API but lacks built-in automatic cleanup and has known performance overhead. Last updated in 2018; no active maintenance observed.

devops

npm install async-local-storage

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · ASYNC-LOCAL-STORAG

async-local-storage

devopsjavascriptv2.3.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import als from 'async-local-storage'

✗ const als = require('async-local-storage')

CommonJS require works in Node <14; ESM import is preferred for modern code.

enable

✓ import { enable } from 'async-local-storage'

✗ const enable = require('async-local-storage').enable

Named exports are available; require destructuring works but ESM is safer.

scope

✓ import { scope } from 'async-local-storage'

✗ als.scope()

Must be called within a context where async_hooks tracking is active, typically after enable().

set/get

✓ import { set, get } from 'async-local-storage'

✗ als.set(...)

Named import avoids globals; set/get are used like als.set/als.get once imported.

Basic usage: enable async hooks, create a scope, set and get a value within the same call chain.

import als from 'async-local-storage'; als.enable(); als.scope(); als.set('requestId', 'abc123'); setTimeout(() => { const id = als.get('requestId'); console.log('Retrieved in timeout:', id); }, 10); als.disable();

Debug

Known issues

gotchaenable() must be called before using scope/set/get; otherwise operations silently fail.

fix

Call als.enable() once at startup before any async operations.

affects: >=1.0.0

gotchascope() changes the call chain top — parent values are no longer accessible after calling scope().

fix

Use scope() only when you want a fresh context; otherwise skip it.

affects: >=1.0.0

deprecatedasync_hooks used by this package can degrade performance; use with caution in high-throughput apps.

fix

Consider alternatives like cls-hooked or AsyncLocalStorage (built-in in Node 12+).

affects: >=1.0.0

gotchaset() with linkedTop=true ties value to the top of the call chain; may cause unexpected sharing.

fix

Use linkedTop only when you explicitly want to share across sub-chains.

affects: >=1.0.0

Errors

Common errors & fixes

ReferenceError: als is not defined

Missing import or require of async-local-storage.

fix

Add const als = require('async-local-storage'); or import als from 'async-local-storage';

TypeError: als.enable is not a function

Import incorrectly (e.g. default vs named export mismatch) or package not installed.

fix

Use const als = require('async-local-storage'); als.enable();

AssertionError: als.get('id') returns undefined

enable() not called before set()/get(), or scope() changed context.

fix

Ensure als.enable() is called before any async operations and scope() is used appropriately.

Error: Cannot find module 'async-local-storage'

Package not installed.

fix

Run npm install async-local-storage

async_hooks is not available in this Node version

Node <8.0.0 or running in a browser without polyfill.

fix

Upgrade Node to >=8.0.0 or use a different library that does not rely on async_hooks.

Upgrade

Version history

2.3.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

7 hits · last 30 days

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OpenAI (training)

Resources

githubhttps://github.com/vicanso/async-local-storage ↗

packageasync-local-storage ↗

homepagehttps://github.com/vicanso/async-local-storage#readme ↗